Method for multi-channel operation in a vehicular network and vehicular network

ABSTRACT

A method for providing, by a service provider, a service in a vehicular network including a control channel for exchanging management frames among communicating entities and a plurality of service channels for exchanging application-specific information among the communicating entities, includes receiving, from a service user, a request for a requested service. The method further includes performing channel load estimation on one or more of the plurality of service channels, and performing, based on the results of the channel load estimation and a priority of the requested service, scheduling the requested service to one of the plurality of service channels.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/500,124 filed on Jan. 30, 2017, which is a U.S. National StageApplication under 35 U.S.C. § 371 of International Application No.PCT/EP2016/062564 filed on Jun. 2, 2016, which claims benefit toEuropean Patent Application No. EP 15171035.7 filed on Jun. 8, 2015, andwhich applications are hereby incorporated by reference herein. TheInternational Application was published in English on Dec. 15, 2016 asWO 2016/198320 A1 under PCT Article 21(2).

FIELD

The present invention generally relates to a method for multi-channeloperation in a vehicular network, as well as to a vehicular network withmulti-channel operations support.

BACKGROUND

For the purpose of road safety and traffic efficiency, vehicularnetworks will primarily operate in the 5.9 GHz frequency band. Byregulation, this spectrum is split into several wireless channels of 10MHz bandwidth. In order to efficiently utilize the spectrum, vehiclesneed to operate on multiple channels simultaneously, also referred to asmulti-channel operation (MCO). IEEE 1609.4 (for reference, see IEEE,IEEE 1609.4-2010—IEEE Trial-Use Standard for Wireless Access inVehicular Environments (WAVE)—Multi-Channel Operation, IEEE Std., 2010)is a standard for MCO for the IEEE 1609 protocol stack. It relies onchannel switching or alternating between a Control Channel (CCH) andService Channels (SCHs) for single-radio transceivers, and between SCHfor dual-radio transceivers; the latter when considering that one radiois constantly tuned in the CCH. However, in addition to not consideringthe application relevance, this time division oriented channel switchingapproach was shown to be inefficient in channel utilization (forreference, see Chen, Q., Jiang, D., & Delgrossi, L. (2009). IEEE 1609.4DSRC Multi-Channel Operations and Its Implications on Vehicle SafetyCommunications. In Vehicular Networking Conference (VNC), 2009 IEEE (pp.1-8)). Also, simTD (for reference, see H. Stubing, M. Bechler, D.Heussner, T. May, I. Radusch, H. Rechner, and P. Vogel: “sim td: acar-to-x system architecture for field operational tests [topics inautomotive networking]”, in IEEE Communications Magazine, vol. 48, no.5, pp. 148-154, 2010), one of the major field trials for inter-vehicularcommunication, has developed architecture and message formats for MCO.

The design of a MCO solution is challenging due to the characteristicsof VANETs: Their applications have specific requirements with distinctrequirements, particularly for latency and reliability, which MCO mustprovide support. Furthermore, the decentralized organization of VANETSand their dynamic and ephemeral characteristics creates challenges inprotocol design, where nodes only have local information available fordecision making. MCO can be enabled by single or dual-radiotransceivers. Although the initial release of inter-vehicularcommunication systems is based on single-radio transceiver, it isforeseen that the next generations rely on dual-radio transceiversettings for improved performance.

SUMMARY

In an embodiment, the present invention provides a method for providing,by a service provider, a service in a vehicular network including acontrol channel for exchanging management frames among communicatingentities and a plurality of service channels for exchangingapplication-specific information among the communicating entities. Themethod includes receiving, from a service user, a request for arequested service, performing channel load estimation on one or more ofthe plurality of service channels; and performing, based on the resultsof the channel load estimation and a priority of the requested service,scheduling the requested service to one of the plurality of servicechannels.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in even greater detail belowbased on the exemplary figures. The invention is not limited to theexemplary embodiments. All features described and/or illustrated hereincan be used alone or combined in different combinations in embodimentsof the invention. The features and advantages of various embodiments ofthe present invention will become apparent by reading the followingdetailed description with reference to the attached drawings whichillustrate the following:

FIG. 1 is a schematic view illustrating a highway scenario with staticservice providers and mobile service providers operating on multiplechannels in which an embodiment of the present invention can be suitablyapplied;

FIG. 2 is a diagram illustrating components of a communicating entityfor executing a multi-channel operation procedure in accordance with anembodiment of the present invention;

FIG. 3 is a diagram illustrating a service provider's multi-channeloperation flowchart in accordance with an embodiment of the presentinvention; and

FIG. 4 is a diagram illustrating a service user's multi-channeloperation flowchart in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION

Mechanisms for efficient channel load estimation and switching whenthere is a need to switch the channel dynamically in order to supportvarious applications/services in vehicular networks have not beendetailed by the above mentioned efforts. Most of the existing workfocuses on channel utilization, synchronization, and related lower-layerperformance indicators.

A method for multi-channel operation in a vehicular network and avehicular network with multi-channel operations support are describedherein in which the efficiency of multiple channel usage is enhanced,while ensuring stability and continuity in the service channels, inparticular for prioritized applications and high priority services.

A method for multi-channel operation in a vehicular network is describedherein, wherein said network includes a plurality of communicatingentities, said communicating entities being designated either as serviceprovider or as service user, a control channel for exchanging managementframes among said communicating entities, and at least two differentservice channels for application-specific information exchanges amongsaid communicating entities. The method includes performing, by saidcommunicating entities, channel load estimation through a combination ofphysical channel measurements and an analysis of the transmitted serviceannouncement messages (SAM) generated by service providers, and based onthe results of said channel load estimation together with existingservices on said service channels and user and/or application preferenceconfigurations, performing dynamic service channel switching to eitherprovide or consume a service.

A vehicular network with multi-channel operation support is describedherein, said network including a plurality of communicating entities,said communicating entities being designated either as service provideror as service user, a control channel for exchanging management framesamong said communicating entities, and at least two different servicechannels for application-specific information exchanges among saidcommunicating entities, wherein said communicating entities areconfigured to perform channel load estimation through a combination ofphysical channel measurements and an analysis of the transmitted serviceannouncement messages (SAM) generated by service providers, and based onthe results of said channel load estimation together with existingservices on said service channels and user and/or application preferenceconfigurations, to perform dynamic service channel switching to eitherprovide or consume a service.

AA practical, dynamic channel switching MCO solution is described hereinthat takes into account (estimated) channel load, existing services onservice channels and user and/or application preference configurations,defined for preferably both service providers and service users. Thechannel load estimation mechanism in accordance with the presentinvention relies on combined physical measurements and ServiceAnnouncement Message overhearing on the control channel. By exploitingcontrol channel announcements, stability is achieved in servicechannels. Consequently, a method according to an embodiment of thepresent invention can also be applied as an improvement of existingstandardized solutions for vehicular congestion control.

Embodiments of the present invention can define new Service Provideroperation for application prioritization channel and channel switchingthat takes into account dynamic information on channel load andapplication requirements. Furthermore, embodiments of the presentinvention can define new Service User operation for channel switchingbased on user preferences and application priorities. By providing theability to prioritize the applications/services on both the ServiceProvider and Service User side, these embodiments are able toefficiently support any future applications/services.

In contrast to existing MCO solutions, embodiments of the presentinvention can take into account the dynamic environment generated by acombination of various applications provided by both mobile and staticproviders and limited channel resources. In particular, in contrast toIEEE 1609.4, as mentioned above, which is application-static andchannel-load-static, meaning the channel switching does not occur due toapplication requirements, embodiments of the present invention canrealize a dynamic solution, i.e., service channels are dynamicallyswitched according to relevant input information from applications anddue to channel conditions. Embodiments can take the input from usermechanisms to adapt to dynamic application and channel environments.

It could be shown in simulations, where a large number of platoons werepassing near RSUs and mobile service providers, which generated load upto the maximum allowed per channel, that the method according to thepresent invention works particularly well in such challenging anddynamic highway scenarios. By applying the present invention, each SU isable to consume its highest priority application even in case of fullyloaded channels. Furthermore, a method according to an embodiment of thepresent invention effectively enables prioritization; given scarceresources, the highest priority applications do not suffer due to thepresence of lower priority applications.

According to an embodiment, each communicating entity/node (e.g., eithera vehicle or roadside unit, RSU) may continuously log the ServiceAnnouncement Messages (SAMs) transmitted on CCH by each serviceprovider. SAMs may be configured to contain information that indicates,e.g., service priority, service channel number, the Protocol Identifierand/or content type of the message to be delivered by a particularservice. For each SCH, the communicating entity may keep an estimate ofthe channel load based on the information contained in the SAMs. In thecontext of the analysis of SAMs, the communicating entities may takeinto consideration the relevance of each SAM based on the time periodafter reception of the respective SAM and/or the distance of therespective communicating entity to the sender of the respective SAM.Specifically, a time window and a weighing function may be in place thatdetermine how relevant each received SAM is based on any of the abovecriteria, i.e.: 1) how long ago the SA message was received; and 2) thedistance to the sender of SA message.

According to an embodiment, the physical channel measurements may beperformed passively for those channels a communicating entity iscurrently switched on. In other words, each communicating nodecalculates the channel load (e.g. by using Channel Busy Ratio (CBR) orsimilar methods) for channels it is currently on, i.e. CCH and one ofthe SCHs, in a passive mode whereby the node does not move to anyparticular channel just to measure that channel's load; rather it takesthe opportunity to measure the load since it is already tuned to thatchannel.

According to an embodiment, it may be provided that communicatingentities participating in a cooperative application that includes oreven requires continuous exchange of messages among the participants(e.g., vehicles forming a platoon, cooperative cruise control, etc.),provide collected information about their channel measurements and aboutoverheard SAMs to a coordinating entity of the corporative application.For instance, the participants of a corporative application may spend aportion of their channel time scanning other channels and report thescanning results to said coordinating entity of said corporativeapplication.

Specifically, in a cooperative application the channel load estimationprovisions for using the continuous message exchange as an input asfollows: Since multiple nearby vehicles communicate, they can alsocollect information about their channel measurements and overheard SAMsand provide that information to coordinating vehicle (e.g. platoonleader). This information can contain load estimates from multiplechannels, since i) some of the vehicles might receive information notavailable to other vehicles in the platoon; and ii) in a coordinatedfashion, they can spend some of their channel time scanning otherchannels and reporting the results to the coordinating vehicle. Based onthis input, the platoon leader is able to better estimate the channelload for the entire platoon, as opposed to each vehicle estimating theload by itself.

According to an embodiment, a service provider may be configured todetermine the current number of services per service channel (providedby any of the communicating entities, e.g. ITS-G5 nodes) by tracking theSAMs broadcasted on the control channel. This number of services perservice channel may then be employed as input information for a channelselection algorithm.

According to an embodiment, a service provider may be configured to useuser and/or application preference configurations to determine servicepriorities and to decide which service to advertise in case ofconcurrent services. By providing the ability to prioritize theapplications/services on both the service provider and service userside, the solution is able to efficiently support any futureapplications/services.

According to an embodiment, when a service provider has a new service toadvertise, the service provider may choose the same service channel thatthe service provider's other services are using if the resulting load onthat service channel is below a predefined maximum channel load. If theservice provider does not have any currently advertise services, it maychoose the service channel with the currently lowest channel load forthe new schedule.

According to an embodiment, if there are parallel/concurrent servicesfrom a service provider and the load on the service channel the serviceprovider is transmitting on exceeds a predefined maximum channel load,the service provider may drop lower priority services of its concurrentservices. Each service provider may repeat this procedure until thenumber of services and their resulting load is equal or less thanmaximum channel load. Dropped services may be rescheduled later (after acertain amount of delay and if channel load is below maximum).

According to an embodiment, a service user may be configured to monitor(regularly or continuously) the SAMs broadcast on the control channel.Based thereupon, a service user may perform a check whether any of itstransceivers is tuned on the service channel with the currently highestpriority service. This check may be performed in regular intervals, inparticular upon the reception of a SAM on the control channel.

According to an embodiment, when a service, a service users interestedin, is being advertised by a service provider, the service user may moveone of its transceivers (i.e. one that is not tuned to the controlchannel) to the service channel the advertised service is on. When aservice is being announced having a higher priority than the servicewith the currently highest priority (which a service user can get toaware of by tracking the SAMs on the control channel, as mentionedabove), the service user may switch to the service channel where thathigher priority service is provided. In case of concurrent services withthe same priority, the service user may select one of the concurrentservices randomly. By performing dynamic channels switching as describedabove, which takes into account dynamic information on channel load andapplication requirements/prioritization, it is ensured that the highestpriority service in the area is being serviced in a reliable andcontinuous fashion.

According to an embodiment, the user preference database and/or theservice/application preference database that are maintained in thevehicles (e.g. stored on a hardware platform that is part of thevehicle's on-board unit, OBU) may be set as default (i.e. upon deliveryof the vehicles) and may be configured to allow users to definecustomized preferences.

Hereinafter, the term ‘CCH’ will be generally employed to denote acontrol channel, which is a radio channel used for exchange ofmanagement frames. Similarly, the term ‘SCH’ will be employed to denoteservice channels, which are secondary channels used forapplication-specific information exchanges.

FIG. 1 depicts a typical highway scenario, in which embodiments of thepresent invention can be suitably applied. Generally, in order toinitiate communications on an SCH, an RSU or an OBU (On-Board Unit)transmits dedicated announcement frames on the CCH to advertise offeredservices available on that SCH. Such a device is called a s serviceprovider. An OBU receives the announcement on the CCH and generallyestablishes communications with the service provider on the specifiedSCH; such a device will be termed service user hereinafter.

The highway scenario shown in FIG. 1 includes multiple service providers101 (hereinafter briefly SPs), both mobile and static: the SP1-SP3 areRSUs 102 that can provide different type of services to vehicles (e.g.,safety message relaying, traffic information, etc.). In addition, thereare three platoons (P1-P3), where a platoon leader provides a mobileservice (i.e., platoon leader is a mobile SP 103) that other vehicles ina platoon are using, thus functioning as service users 104 (hereinafterbriefly SUs). For the sake of completeness it is noted that FIG. 1depicts further vehicles that function as SUs 104 individually, i.e.without being participant of a platoon.

Generally, an embodiment of the present invention described hereinafterin detail focuses on designing an MCO solution for an ITS-G5 basedmulti-transceiver (or at least dual transceiver) design for V2X systems(which is the proposed design for ETSI/C2C-CC) that is able to exploitcontrol channel announcements to achieve stability in service channels,in particular for high priority services. Supporting a large number ofsuch services would not be possible on a single channel. An embodimentof the present invention can provide mechanisms for efficient use ofmultiple channels to enable a larger number of services and to enablefuture applications in vehicular networks through multi-channeloperation.

Channel load estimation for multiple channels is not trivial unless thenumber of deployed transceivers is the same as the number of existingchannels. Specifically, certain amount of time is lost when a radiomoves from one channel to another (i.e., the channel switching time isnot negligible). IEEE 1609.4 defines minimum channel switchingperformance to be 100 ms (i.e., the transceiver should be able to switchchannels at least 10 times per second). Furthermore, besides channelswitching, to estimate the load on the channel, the transceiver needs tostay on the channel for a certain period of time. This implies that: 1)in case when the number of channels is large, comparatively more time isspend switching across channels and measuring load; and 2) inherently,the measured load is an estimate of the channel load across a longerperiod of time (since the assumption is that the transceiver cannot betuned to a channel all the time). For these reasons, embodiments of thepresent invention apply a new channel load estimation algorithm, as willbe described hereinafter in detail.

According to a specific implementation of an embodiment of the presentinvention, a method for Multi-Channel Operation in vehicular network maycomprise the following steps:

-   -   1) Applying a channel load estimation algorithm through combined        active physical channel estimation and by analyzing the        transmitted Service Announcement Messages generated by Service        Providers;    -   2) Loading User and App preference configurations for both SP        and SU;    -   3) Switching the service channel to either provide a service (in        case of SP) or consume a service (in case of SU); and    -   4) Repeating above steps concurrently on all communicating        entities designated as either the SP or SU.

Turning now to FIG. 2, components of a communicating entity 200 areillustrated for executing a multi-channel operation (MCO) procedure inaccordance with embodiments of the present invention, independent ofwhether this communicating entity 200 functions as an SP 101 or as an SU104. Accordingly, each communicating entity 200 comprises an applicationunit 201, hereinafter briefly AU, and a communication control unit 202,hereinafter briefly CCU, which both may be implemented as hardwareplatforms. Management entities 209 and 210, respectively, provide systemconfiguration parameters corresponding to system entity AU and CCU,respectively. In relevance to embodiments of the present inventionconfiguration parameters pertaining to channel load measurements arepart of management entity 210. On the other hand, configurationparameters pertaining to the channel load estimation and selectionalgorithm are part of management entity 209.

The AU 201 is configured to execute the channel load estimation forservice channels SCH. In the illustrated embodiment it is assumed thatin addition to the CCH there are a total number of four servicechannels—SCH1-SCH4—in place, which are shown at the bottom of FIG. 2.The channel load estimation is performed by channel load estimationmodule 203. In accordance with the present invention channel loadestimation is performed through a combination of physical channelmeasurements and an analysis of service announcement messages (SAMs)transmitted by service providers 101 within the network. Consequently,channel load estimation module 203 receives as channel load estimationinput information from service announcements database 204 and fromphysical channel load estimation database 205.

Since there will be an inevitable interaction (and possibly somecontradiction) between channel load estimated via SAMs on the one handand channel load measured by physically listening on the channel on theother hand, the channel load estimation module 203 may apply aresolution mechanism as follows: If both are available, the channel loadestimation module 203 may trust physical measurements, and it may usethe SAM-derived load for estimating future demand on the channel.Alternatively, if both are available, the channel load estimation module203 may perform averaging:CL _(SCH) =a*CL _(SAM) +b*CL _(PHY),where a and b are weights and CL_(X) is the channel load estimate forSAM- and PHY-based channel load estimation.

In any case, the resulting channel load information is forwarded tochannel selection module 206. Together with information on userpreferences and application priorities received from User PreferencesDatabase 207 and App Preferences Database 208, respectively, as well asapplication and/or facility related information management entity 209,the channel selection module 206 determines in a dynamic fashion asuitable SCH for putting a new service on, as will be explained in moredetail in connection with FIG. 3 (for the case of an SP 101) and FIG. 4(for the case of an SU 104).

In the illustrated scenario the channel selection module 206 determinedservice channel SCH X for the new service in question. This informationis forwarded to the CCU 202, which comprises a management entity 210that processes this information down the protocol stack. Finally, at thephysical ‘PHY’ layer of the protocol stack a transceiver of therespective communicating entity 200 is switched to the respectiveservice channel SCH X (while a different transceiver of thecommunicating entity 200 remains on the CCH).

In order to continuously enable efficient and reliable channel loadestimation, the management entity 210 of the CCU 202 counts, at thetransport layer, received SAMs broadcast on the CCH and reports thenumber of counted SAMs back to the physical channel load estimationdatabase 205 of AU 201.

FIG. 3 is a flowchart illustrating details of the MCO operationsperformed by a service provider, SP 101. The SP 101 may be a static SP,e.g. deployed in form of roadside unit, RSU 102, or a mobile SP 103,e.g. a vehicle functioning as a coordinating entity of a cooperativeapplication (for instance, the leader of a platoon).

In a first step, as shown at 301, the SP configuration is loaded. Thisconfiguration may include user preference configurations that can beloaded from a dedicated user preferences database (e.g., the UserPreferences database 207 shown in FIG. 2) and or application preferenceconfigurations that can be loaded from a dedicated applicationpreferences database (e.g., the App Preferences database 208 shown inFIG. 2). Once the SP configuration is loaded, the SP waits to receive arequest from any service user within its coverage area, as shown at 302.

Once such a request is received, the SP checks in a first step, shown at303, whether it is already providing the requested service. If so, theSP checks in a second step, shown at 304, whether the channel load onthe current SCH is lower than a predefined maximum admissible load. Ifso, the SP schedules the requested service to the current SCH for apredefined duration T_(Service), as shown at 307. On the other hand, ifthe check performed at 303 yields that the SP is not yet providing therequested service, at 305, the SP checks the channel node and each ofthe existing SCHs and further, shown at 306, whether the channel load onthe SCH with the lowest load exceeds a predefined maximum admissibleload. If not, the SP proceeds with step 307, i.e. schedules therequested service to the current SCH for a predefined durationT_(Service).

Once the requested service is scheduled on a particular SCH, the SPsends the service on this SCH with a predefined frequency (in FIG. 3denoted by ‘Y’ Hz) and, in addition, transmits SAMs on the CCH with apredefined frequency (in FIG. 3 denoted by ‘X’ Hz), as shown at 308.This process is repeated as long as the channel load on the current SCHis below a predefined maximum admissible threshold, as shown at 309. Incase this threshold is exceeded, as shown at 310, the SP selects theservice with the currently lowest priority and stops providing thisservice. Afterwards, as shown at 311, the SP waits for a predefinedperiod of time (in FIG. 3 denoted by ‘Z’ ms) and, after expiry of thistime period, the SP tries to reschedule the stopped service by returningto step 303.

In case the SP notes in step 303 that a requested service is alreadyprovided, but in step 304 that the channel load on the current SCHexceeds a predefined maximum admissible threshold, the SP checks in step312 whether the requested service has a lower priority than all otherservices the SP is currently running. If so, the SP turns to step 311,i.e. waits for a predefined period of time and tries re-reschedulingafter this period of time. On the other hand, if it turns out in step312 that the SP is running services having a lower priority than thecurrently requested service, the SP proceeds with step 307, i.e. itschedules the requested service to the current SCH for a predefinedduration T_(Service). By doing so, the multi-channel operation procedureaccording to embodiments of the invention achieves a situation in whichSCHs are not getting overloaded by services with lower priority, and inwhich stability and continuity is ensured in the service channels forhigher priority services and/or prioritized applications.

FIG. 4 is a flowchart illustrating details of the corresponding MCOoperations performed by a service user, SU. In this embodiment it isassumed that the SU, like the SP, uses a User and App preferenceconfigurations for distinguishing service priorities. Once the SUconfiguration is loaded at 401, the SU monitors the CCH for SAMs, asshown at 402. When there is a service advertised by an SP that the SU isinterested in, SU moves its second transceiver (while the firsttransceiver being tuned on the CCH) to the SCH that this service is on.Then, at 403, the SU performs a check whether its second transceiver ison the SCH with highest priority service. If so, at 404, the SU consumesthis service on the current SCH. If not, at 405, the SU first switchesto the SCH with the highest priority service and then consumes theservice on this SCH. As already indicated above, to ensure that thehighest priority service in the area is being serviced, the SU tracksthe SAMs on the CCH. If a higher priority service is announced via anSAM on the CCH and the respective SAM is received at the SU, as shown at406, the SU returns to step 405, i.e. moves to the SCH service channelwhere that service is provided. In the case of concurrent services withthe same priority, it may be provided that the algorithm selects oneservice randomly. Finally, at 407, the SU performs a check whether anyof the currently consumed services is still active. If so, the SUreturns to step 404, otherwise the SU returns to step 402.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive. Itwill be understood that changes and modifications may be made by thoseof ordinary skill within the scope of the following claims. Inparticular, the present invention covers further embodiments with anycombination of features from different embodiments described above andbelow.

The terms used in the claims should be construed to have the broadestreasonable interpretation consistent with the foregoing description. Forexample, the use of the article “a” or “the” in introducing an elementshould not be interpreted as being exclusive of a plurality of elements.Likewise, the recitation of “or” should be interpreted as beinginclusive, such that the recitation of “A or B” is not exclusive of “Aand B,” unless it is clear from the context or the foregoing descriptionthat only one of A and B is intended. Further, the recitation of “atleast one of A, B and C” should be interpreted as one or more of a groupof elements consisting of A, B and C, and should not be interpreted asrequiring at least one of each of the listed elements A, B and C,regardless of whether A, B and C are related as categories or otherwise.Moreover, the recitation of “A, B and/or C” or “at least one of A, B orC” should be interpreted as including any singular entity from thelisted elements, e.g., A, any subset from the listed elements, e.g., Aand B, or the entire list of elements A, B and C.

What is claimed is:
 1. A method for providing, by a service provider, aservice in a vehicular network including a control channel forexchanging management frames among communicating entities and aplurality of service channels for exchanging application-specificinformation among the communicating entities, the method comprising:receiving, from a service user, a request for a requested service;performing channel load estimation on each of the plurality of servicechannels; and performing, based on the results of the channel loadestimation and a priority of the requested service, scheduling therequested service to one of the plurality of service channels based onthe results of each of the channel load estimations.
 2. The methodaccording to claim 1, wherein the service priority of the requestedservice is determined based on user and/or application preferenceconfigurations.
 3. The method according to claim 1, further comprising,transmitting service announcement messages (SAMs) on the control channelwith a predefined frequency.
 4. A communicating entity comprising ahardware platform configured to perform the method of claim
 1. 5. Amethod for providing, by a service provider, a service in a vehicularnetwork including a control channel for exchanging management framesamong communicating entities and a plurality of service channels forexchanging application-specific information among the communicatingentities, the method comprising: receiving, from a service user, arequest for a requested service; performing channel load estimation onone or more of the plurality of service channels; and performing, basedon the results of the channel load estimation and a priority of therequested service, scheduling the requested service to one of theplurality of service channels; wherein the performing the channel loadestimation on one or more of the plurality of service channelscomprises: determining whether the requested service is already beingprovided on a current service channel; and if the requested service isalready being provided on the current service channel, performingchannel load estimation on the current service channel, or otherwiseperforming channel load estimation on each of the plurality of servicechannels in order to determine a service channel having a lowest load.6. The method according to claim 5, wherein the scheduling the requestedservice to one of the plurality of service channels comprises: if therequested service is already being provided on the current servicechannel: determining whether the channel load on the current servicechannel is less than a predefined maximum admissible load, and if thechannel load on the current service channel is less than the predefinedmaximum admissible load, scheduling the requested service on the currentservice channel for a predefined duration, or otherwise comparing thepriority of the requested service to priorities of other servicesrunning on the current service channel; or otherwise scheduling therequested service to the service channel having the lowest load.
 7. Themethod according to claim 6, wherein the scheduling the requestedservice to the service channel having the lowest load comprises:determining whether the channel load on the channel having the lowestload is less than the predefined maximum admissible load, and if thechannel load on the channel having the lowest load is less than thepredefined maximum admissible load, scheduling the requested service onthe service channel having the lowest load for a predefined duration,otherwise comparing the priority of the requested service to prioritiesof other services running on the service channel having the lowest load.8. The method according to claim 7, wherein if the priority of therequested service is lower than the priorities of the other servicesrunning on the service channel having the lowest load, the methodfurther comprises waiting for a predetermined period of time andattempting to reschedule the requested service thereafter.
 9. The methodaccording to claim 6, wherein if the priority of the requested serviceis lower than the priorities of the other services running on thecurrent service channel, the method further comprises waiting for apredetermined period of time and attempting to reschedule the requestedservice thereafter.
 10. A method for providing, by a service provider, aservice in a vehicular network including a control channel forexchanging management frames among communicating entities and aplurality of service channels for exchanging application-specificinformation among the communicating entities, the method comprising:receiving, from a service user, a request for a requested service;performing channel load estimation on one or more of the plurality ofservice channels; and performing, based on the results of the channelload estimation and a priority of the requested service, scheduling therequested service to one of the plurality of service channels; whereinthe performing channel load estimation on the one or more of theplurality of service channels comprises performing, for each of the oneor more of the plurality of service channels, a combination of physicalchannel measurements and an analysis of transmitted service announcementmessages (SAM) generated by the service provider.
 11. The methodaccording to claim 10, wherein the performing the analysis of thetransmitted SAMs includes considering a relevance of each SAM based on atime period after reception of the respective SAM and/or a distancebetween a sender and a receiver of the respective SAM.
 12. A method forreceiving, by a service user, a service in a vehicular network includinga control channel for exchanging management frames among communicatingentities and a plurality of service channels for exchangingapplication-specific information among the communicating entities, themethod comprising: monitoring the control channel for serviceannouncement messages (SAMs) via a first transceiver tuned to thecontrol channel; tuning a second transceiver to a selected servicechannel providing a selected service; determining whether the selectedservice channel is a service channel with the highest priority service;and consuming the selected service on the selected service channel ifthe selected service channel is the service channel with the highestpriority service or otherwise tuning the second transceiver to theservice channel with the highest priority service.
 13. The methodaccording to claim 12, wherein if a service is announced having a higherpriority than the selected service, the method further comprisesswitching to a service channel where the announced service is provided.14. The method according to claim 12, wherein if concurrent serviceswith a same priority are provided, the method further comprisesselecting one of the concurrent services randomly.
 15. The methodaccording to claim 14, wherein the selecting one of the concurrentservices randomly is performed by an algorithm.
 16. The method accordingto claim 15, wherein the algorithm is a service selection algorithm thattakes into account a number of services per service channel.
 17. Themethod according to claim 16, wherein if a service is announced having ahigher priority than the selected service, the method further comprisesswitching to a service channel where the announced service is provided.18. The method according to claim 12 comprising selecting betweenmultiple concurrent services with a same priority based on an algorithmthat considers a number of services per service channel.
 19. Acommunicating entity comprising a hardware platform configured toperform the method of claim 12.